Funds are requested to support the second phase of an ongoing research initiative directed at clarifying the association of children's language impairments and attention deficits. In Phase 1, the psycholinguistic and socioemotional profiles of narrowly defined and independently verified clinical groups (SLI and combined-type ADHD) were investigated to identify key clinical markers which best differentiated attention deficits and language impairments form each other and form typical development (R03 DC008382). Phase 2 moves the initiative forward by examining variation associated with the two most efficient language indices across a larger age span and within a more diverse community-based sample. Nine hundred and twenty students will be administered a brief screening of their proficiencies with past tense marking and sentence recall (230 x K-3rd grade). Cutoff scores will be based on study sample's characteristics. Out of the pool of screened participants, 260 low scoring students (< 16th %ile) and 360 average scoring (> 15th %ile) will participate in confirmatory evaluations of their language, attention, reading, nonverbal, and working memory skills. Blinding procedures will be used to reduce examiner bias. The specific aims of the project are (1) to determine the adequacy of past tense- marking and sentence recall indices for identifying language impairments within a community based study sample of early elementary students. (2): to determine the risk of co-occurring attention deficits within students who have confirmed language impairments and (3): to evaluate different models of the association of language impairment and attention deficit among young children. The possibility that associations of language impairment and attention deficits might be different across grade groups will be examined. The proposed research impacts upon several key public health concerns. In addition to substantial familial and societal costs associated with addressing language impairments and attention deficits, both of these disorders have been shown to be contributors to long-standing academic, socioemotional, and vocational difficulties. Given the limited resources available to practitioners and the health risks associated with missed diagnosis, misdiagnosis, and untreated comorbidity, it is crucial that identification is accurate, efficient, and timely so children can receive the most benefit from therapeutic services. PUBLIC HEALTH RELEVANCE: Developmental language impairments and attention deficits represent the two most common reasons young children are referred for clinical services. These disorders frequently co-occur and both conditions represent risk factors for the emergence academic and social difficulties, however, interrelationships between these areas remains unclear. The goals of the proposed research are to clarify the mechanisms linking language impairments and attention deficits and to advance the translation of behavioral phenotypes of language impairment (LI) into clinical protocols appropriate for differential diagnosis and the identification of cases of LI+ADHD comorbidity and